Evolutionary Mismatch Theory
So have you heard about the Evolutionary Mismatch Theory? I believe you might know the concept, but probable didn’t put a name to it. This is the concept that refers to evolved traits that were once advantageous but became maladaptive (more harmful than helpful) due to changes in the environment. This is the idea that traits that were evolved in one environment have the potential to be disadvantageous in a different environment. These changes can be existing in the environment over time (climate change) or by being in a a new environment (birds migrating). Another kind of change is human caused (anthropogenic). We have really been able to see this, especially in the last 100 years. Evolution is usually gradual and environmental changes often occur quicker on a geological scale, there is always a period of “catching-up” as the population evolves to become adapted to the environment. It is this temporary period of “disequilibrium” that is referred to as mismatch. Mismatched traits are ultimately addressed in one of several possible ways: the organism may evolve such that the maladaptive trait is no longer expressed, the organism may decline and/or become extinct as a result of the disadvantageous trait, or the environment may change such that the trait is no longer selected against.
Now lets talk about us. We are predisposed to maintain our homeostasis, especially when storing energy as fat. Homeostasis is your body regulating itself to stay alive….internal organs operating and functioning. This trait serves as the main basis for the “thrifty gene hypothesis”, the idea that “feast-or-famine conditions during human evolutionary development naturally selected for people whose bodies were efficient in their use of food calories”. Hunter-gatherers, who used to live under environmental stress, benefit from this trait; there was an uncertainty of when the next meal would be, and they would spend most of their time performing high levels of physical activity. Therefore, those that consumed many calories would store the extra energy as fat, which they could draw upon in times of hunger.
As time has passed we have become a species that sits more and food is more readily available. People work at desks or on computers, commute sitting in cars, or spend majority of their time in a small office. Less moving means less energy expenditure or calories burned. What the majority of people eat has changed as well. Instead of living off the land we are eating more processed foods. These foods are high in calories and low in nutrients…..not good! Our caloric intake (food we eat) is more than our energy expenditure (physical activity), thus causing an unhealthy obese species. The “Thrifty Gene” that once benefits humans, now works against us, causing our bodies to store more fat. We also have become more insulin resistance (body no longer responds to insulin secretion so blood glucose levels are unable to be lowered – leading to type 2 diabetes).
How have we adapted to work stress? Our ancestors used to lead very simple lives compared to us. They did not have to worry about bosses, deadlines, or separating their work from home life. We do the complete opposite thought, worry about our bosses, usually have deadlines we need to meet, and have a hard time separating work from home especially with technology. Our stress system reacts to immediate threats or opportunities. We are constantly “fight or flight” mode. There is no down time or separation from work. The modern workplace exploits evolved psychological mechanisms that are aimed at immediate survival or longer-term reproduction. These basic instincts misfire in the modern workplace, causing conflicts at work, burnout, job alienation and poor management practices.
How about eating? In the era of foraging for food, hunter-gatherers rarely knew where their next meal would come from. As a result, filling their stomachs up with lots of food was advantageous since food was scarce. Intense consumption of high-energy foods was selected for when the availability of food was low and it was more difficult to find. Now, food is readily available….think fast food and vending machines. The neurological system that once helped people recognize the survival advantages of essential eating has now become disadvantageous as it promotes overeating. This has become especially dangerous after the rise of processed foods, as the popularity of foods that have unnaturally high levels of sugar and fat has significantly increased.
We need to get back to how our ancestors lived….moving more throughout the day and eating foods that are nutritional dense. Less sitting around and eating fast food! We all so need to separate our work from our personal lives…..more walks in nature and turning the phone off!